Rationalists, Empiricists, Rhetoricians

natural-science types and engineers have completely different intellectual worldviews: the first are empiricists while the second are rationalists. As a biochemist, reading Less Wrong or Slate Star Codex has me screaming at my laptop; not a pretty sight.

rms, comment on “Lawyers Guns and Money” blog, 8 July 2020

C.P. Snow’s two cultures are very English and a bit old-fashioned. I come from a country where most people learn physics and chemistry for 10 to 12 years, and I know both calculus and Latin. This is not so unusual in North America, L. Sprague de Camp was an amateur classicist, a poet, and an aeronatical engineer. So this week, I would like to describe three intellectual cultures which I see.

Rationalists try to understand the world by using a few universal principles and formal logic. Empiricists try to learn about the world by trying different heuristics (rules-of-thumb) on a particular domain and seeing which seem to give good results in particular circumstances. And rhetoricians are not as interested in learning about the world as they are in finding a compelling way to talk about it. When someone makes my soul itch, it is often because they are devoted rationalists or rhetoricians and refuse to play by the the rules I use.

If asked to predict what effect a weapon will have on a target, a rationalist will perform elaborate calculations derived by logical rules from physics principles. An empiricist will set up the target and use the weapon on it then stat working on a back-of-the-envelope model. And a rhetorician will grab at whatever truthy or facty phrases seem likely to convince the audience. Faced with a new problem in the physical world, a rationalist will try to deduce the best approach from universal principles, an empiricist will find an expert and ask about best practices, and a rhetorician will be at a loss.

I met a number of wonderful Mensans, but there were other Mensans who were brain-proud and aggressive about their IQs, who, one got the impression, would like, on being introduced, to be able to say ‘I’m Joe Doakes, and my IQ is 172.’ … They were, as I had been in my youth, forcing their intelligence on unwilling victims. In general, too, they felt underappreciated and undersucessful. … Furthermore, I became uncomfortably aware that Mensans, however high their paper IQ might be, were as likely to be irrational as anyone else. Many of them believed themselves to be part of a ‘superior’ group that ought to rule the world, and despised non-Mensans as inferiors. Naturally, they tended to be right-wing conservatives, and I generally feel terribly out of sympathy with such views.

Isaac Asimov, I, Asimov: A Memoir

We can see these three cultures in science. In the historical sciences like history or geology, scientists are overwhelmingly empiricists. But in fields like engineering or theoretical physics, rationalists have a very strong presence. It is very hard for a rhetorician to be a scientist, but some do make their way in, especially in areas of knowledge which are on the border of science like psychology. In the days of the open web, it was notorious that any crank idea from creationism to Yeti had one or two engineers promoting it. And IEEE Spectrum created a scandal a few years ago by observing that engineers are over-represented in terrorist organizations with religious ideologies. Engineers are not so common in terrorist groups organized around communist ideologies, so it can’t just be that terrorist groups seek recruits with engineering skills. Software developers in California love to promote a group of self-proclaimed “rationalists” in the USA like Eliezer ‘LessWrong’ Yudkowski, Robin ‘Overcoming Bias’ Hanson, Tyler ‘Marginal Revolution’ Cowen, Scott ‘Slate Star Codex’ Alexander, and Julia ‘Rationally Speaking’ Galef (Bryan Caplan might belong there too). As this group took shape out of earlier communities, people with education in the humanities or crafts quietly scattered, because the ways of thinking which make the rationalists brilliant about some topics make them foolish about history and philosophy.

We can also see these three cultures in historical crafts. Some people want to be able to deduce the best way of making a doublet or wielding a sword through universal principles of physics and physiology and economics. But real-world decision making is about tradeoffs and deciding which of several incompatible good things to prefer. Its impossible to get an undisrupted night’s sleep and wake up at 4 am to see an eclipse, or to create steel which is maximally hard and maximally tough. Choosing between these things is like choosing which dish to order at a restaurant, not like filling out an income-tax form. I often warn people not to assume that their big modern educated brain lets them reason how a thing was done without looking to see how experts actually do it. But you can find the same idea from a highly educated bladesmith like Fabrice Cognot:

Maybe it’s not just limited to arms and armour, but one might argue that 3 things dictate the shape (and evolutions) of these objects. The choice of words is poor, but let’s call them Technology, Use and Fashion. And the 3 of them are entwined, inextricably. … Ultimately, I believe that swords are better at what they’re made for, with all the things implied by what’s above. The design of one sword might have been mostly dictated by efficiency in a specific set of conditions, but it cannot escape the influence of the technology that created it, nor the influence of fashion, be it evolutive or, contrarily, inertial, that surrounded it.

Or in other words: there might be swords that were just designed as being ‘good’ looking swords, ie. satisfying more the immaterial part of this triple set of influences I wrote above, than to be ‘good’ at doing more material things for which another sword might perform better.

Fabrice Cognot Re: Medieval Sword Types and Cutting, Schola Gladiatoria Forum 28 March 2012 http://www.fioredeiliberi.org/phpBB3/viewtopic.php?f=3&t=18267

and from thoughtful but not-so-educated tailor and modern dress historian Matthew Gnagy:

I also truly love the few garments which have this kind of construction because they challenge the way people think about making things.

If there is one thing that makes me cringe when discussing historical garments with people, it is the assumption that is often made that the work could be carried out in JUST ONE WAY.

I am frustrated by people who follow the “one true way” mode of thinking because it really limits the our understanding of just how creative historical tradespeople were when it came to innovating for efficiency, or just to make the work more feasible and profitable.

Matthew Gnagy, “Challenging the Status Quo with Respect,” 12 May 2021 https://www.themodernmaker.co/historical-wardrobe-feed/

Its easy to underestimate a culture if you meet it through one of these cultures which is wrong for your taste. The Romans who built bridges and glassworks were not the same kind of thinkers as the flatulent orators and dusty legalists, but the orators and legalists got to write more, and more of what they wrote was selected for copying and recopying. If you want to find empiricists, look for people who engage with the outside world and not just with words and symbols. This Canadian finds these three cultures better at explaining which kinds of people I can have a conversation with than C.P. Snow’s two cultures.

Edit 2023-03-31: someone claiming to be the pseudonymous blogger gwern shows up in that space with chaos-theory denialism (species “if some processes are fundamentally unpredictable because small variations in initial conditions lead to wide differences in outcome after a few iterations, we can just avoid those processes and still control outcomes so there”) https://www.lesswrong.com/posts/epgCXiv3Yy3qgcsys/you-can-t-predict-a-game-of-pinball for the quote see Dyson’s Infinite in All Directions (1985) ch. 10 [available from the Internet Archive]

Edit 2023-06-13: added link to IEEE Spectrum

Edit 2023-07-14: amusingly one of the rationalists wrote a four-sentence summary of these criticisms from 2017 and defends their community by describing it in ways I don’t recognize

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(scheduled 29 June 2021)